Yes. Unlike Krypto, who was a Kryptonian dog - that makes sense, right? - Streaky was an ordinary Earth cat. Occasionally he'd play with a ball of string wrapped around a piece of X-Kryptonite, a bizarre kind of kryptonite that granted superpowers to Earth people and probably shouldn't have been left laying around forgotten in the basement of an orphanage. When he acquired his powers he leapt to the conclusion that a superpowered cat needed a secret identity and a cape; he was as smart as a human while the empowerment lasted. When it wore off, awkwardly, he was just a cat again and couldn't remember that he needed to recharge from that particular cat toy. So Streaky's appearances were intermittent.

(Why do I remember this and not my college mathematics? My brain has curious priorities.)